1. Field of the Invention
This invention pertains generally to organic electroluminescent displays, and more particularly to methods for conserving power consumed by organic electroluminescent displays.
2. Description of Related Art
Liquid crystal displays (LCDs) are widely used for portable computers and other products. One major disadvantage of an LCD is that an LCD emits no light; only the transparency of an LCD changes by adding or not adding a voltage. To obtain a high contrast, an LCD requires a backlight. Unfortunately, a backlight lamp consumes much power, e.g., more than one-half of the total power that a laptop personal computer (PC) consumes. The power consumption of the LCDs is an important matter for battery operated portable products.
Current state-of-the art displays include organic electroluminescent (OEL) displays. OEL displays are slowly being introduced into the electronics market. Unlike LCDs, each pixel on an OEL display emits light. Therefore, a backlight is not required. Further, OEL displays can be slimmer than LCDs. It is likely that in many applications LCDs will be replaced with OEL displays in the near future.
As stated above, OEL displays emit light. It happens that darker colors consume less power than brighter colors. As such, darker colors are preferable for power saving. However, white, or other brighter colors, are commonly used as background colors for windows in a PC, and these colors increase the power consumption of OEL displays. Accordingly, if brighter colors occupy most areas of the display screen, a color reverse might be good in order conserve power consumption. Microsoft Windows OS, for example, has such a color reverse feature. A user can change the display mode in a display appearance window. Unfortunately, this feature can only be applied to Windows graphic objects; that is, window background, frames, menus, etc. Many web pages use white as a background color, but this background color remains the same regardless of user Windows settings. Therefore, the Windows color reverse feature is not beneficial for power conservation. In order to maximize power conservation, all brighter colors on the display screen should be changed to darker ones.
The present invention recognizes the present drawbacks and provides a solution to one or more of the problems associated therewith.